Wednesday, April 30, 2014
About Head Gaskets
Head gaskets serve a major purpose, and without them, or with faulty ones, car engines would run terrible, if at all. These gaskets are specially engineered to withstand extreme heat and compression that is built up within the engine providing an air tight seal. Understanding how head gaskets work is important to proper car maintenance.
Identification
The head gasket is located between the engine block and the head. The head bolts on top of the engine block and the valve cover bolts on top of the head. The head gasket is made of metal and is a one-piece gasket.
Function
The gasket ensures that the compression the engine builds stays within the block and doesnt escape. The gasket also serves to keep any oil from leaking out of the engine, and it provides a separation of oil and coolant within the engine block.
Considerations
To determine if there is a head gasket leak, start the engine, and before it gets too hot, run a hand across the seam where the gasket is to "feel" if any pressure is coming out from the area. There should be zero pressure along the seam. Another way would be to check the coolant to see if it has an oily feel or brownish color to it. If the head gasket is leaking from inside the engine block, it will allow oil and coolant to mix together. Looking at the underside of the oil filler cap to see if it is a milky brownish color could also represent a coolant and oil mix. Another inspection would be to check for oil leaks along the gasket seam area. Degrease the area first, run the engine at a high rpm and inspect for leaks. A mechanic can also perform a test to determine any loss of compression through the gasket area.
Time Frame
There isnt a specific time frame involved regarding the life of a head gasket. The original factory gasket may last the life of the engine, or it may break down earlier. The quality of the gasket and driving habits are factors regarding the life of the gasket. Heavy accelerations, as used when racing for instance, creating extreme pressure within the engine, can weaken the gasket prematurely.
Warning
If the the mix of oil and coolant is discovered, replace the gasket right away. If there is no mix in fluids, but only a loss of compression, the gasket still needs to be replaced since as the leak increases, even more compression will be lost and most likely a mix of oil and coolant will also eventually occur.
Prevention/Solution
To replace the gasket, all other surrounding parts in the way must be removed. The mating surfaces for the gasket, which are the top of the engine block and the bottom of the head, must be cleaned thoroughly. Proper gasket sealer should be used and it is critical that the head bolts be torqued down evenly according to manufactures specifications.
Saturday, March 8, 2014
How to Install Cork Replacement Gaskets
Pressed cork gaskets absorb oil that causes the gasket to expand during use. The additional expansion allows the gasket to provide a strong seal between rigid parts. Over time, heat causes cork gaskets to break down and become brittle. Installing a cork gasket correctly extends the life of a mechanical part where it resides and allows you to remove and reinstall a part without ruining the gaskets ability to create a seal.
Instructions
- 1
Remove old gasket material and debris from both the part and engine mounting surfaces by pushing a paint scraper across both surfaces using short strokes.
2Dampen a clean rag with isopropyl alcohol.
3Wipe both surfaces clean with the alcohol-dampened rag. Ensure no dirt or grease remains on either surface.
4Puncture the end of a gasket adhesive tube with the point located on the top of the cap. Apply a 1/8-inch-thick bead of adhesive to the parts gasket mounting flange. Press a cork gasket firmly into the adhesive. Allow the adhesive to dry for 10 to 15 minutes.
5Press the part--gasket side down--onto the mounting flange of the engine. Secure the part to the engine to seat the gasket.